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path: root/rust/kernel/cpu.rs
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5 daysrust: cpu: Add CpuId::current() to retrieve current CPU IDViresh Kumar
Introduce `CpuId::current()`, a constructor that wraps the C function `raw_smp_processor_id()` to retrieve the current CPU identifier without guaranteeing stability. This function should be used only when the caller can ensure that the CPU ID won't change unexpectedly due to preemption or migration. Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
5 daysrust: Use CpuId in place of raw CPU numbersViresh Kumar
Use the newly defined `CpuId` abstraction instead of raw CPU numbers. This also fixes a doctest failure for configurations where `nr_cpu_ids < 4`. The C `cpumask_{set|clear}_cpu()` APIs emit a warning when given an invalid CPU number — but only if `CONFIG_DEBUG_PER_CPU_MAPS=y` is set. Meanwhile, `cpumask_weight()` only considers CPUs up to `nr_cpu_ids`, which can cause inconsistencies: a CPU number greater than `nr_cpu_ids` may be set in the mask, yet the weight calculation won't reflect it. This leads to doctest failures when `nr_cpu_ids < 4`, as the test tries to set CPUs 2 and 3: rust_doctest_kernel_cpumask_rs_0.location: rust/kernel/cpumask.rs:180 rust_doctest_kernel_cpumask_rs_0: ASSERTION FAILED at rust/kernel/cpumask.rs:190 Fixes: 8961b8cb3099 ("rust: cpumask: Add initial abstractions") Reported-by: Miguel Ojeda <ojeda@kernel.org> Closes: https://lore.kernel.org/rust-for-linux/CANiq72k3ozKkLMinTLQwvkyg9K=BeRxs1oYZSKhJHY-veEyZdg@mail.gmail.com/ Reported-by: Andreas Hindborg <a.hindborg@kernel.org> Closes: https://lore.kernel.org/all/87qzzy3ric.fsf@kernel.org/ Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
5 daysrust: cpu: Introduce CpuId abstractionViresh Kumar
This adds abstraction for representing a CPU identifier. Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
2025-05-20rust: cpu: Add from_cpu()Viresh Kumar
This implements cpu::from_cpu(), which returns a reference to Device for a CPU. The C struct is created at initialization time for CPUs and is never freed and so ARef isn't returned from this function. The new helper will be used by Rust based cpufreq drivers. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>